From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id 96CD11B4D6 for ; Thu, 13 Dec 2018 17:38:10 +0100 (CET) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 94D0230832CF; Thu, 13 Dec 2018 16:38:09 +0000 (UTC) Received: from [10.36.112.32] (ovpn-112-32.ams2.redhat.com [10.36.112.32]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E8963611B9; Thu, 13 Dec 2018 16:38:04 +0000 (UTC) To: Jens Freimann , dev@dpdk.org Cc: tiwei.bie@intel.com, Gavin.Hu@arm.com References: <20181213123453.15035-1-jfreimann@redhat.com> From: Maxime Coquelin Message-ID: <9b395ae1-712f-5d7b-5561-7bd0e55df187@redhat.com> Date: Thu, 13 Dec 2018 17:38:02 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <20181213123453.15035-1-jfreimann@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Thu, 13 Dec 2018 16:38:09 +0000 (UTC) Subject: Re: [dpdk-dev] [PATCH v12 00/10] implement packed virtqueues X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 13 Dec 2018 16:38:11 -0000 On 12/13/18 1:34 PM, Jens Freimann wrote: > This is a basic implementation of packed virtqueues as specified in the > Virtio 1.1 draft. A compiled version of the current draft is available > at https://github.com/oasis-tcs/virtio-docs.git (or as .pdf at > https://github.com/oasis-tcs/virtio-docs/blob/master/virtio-v1.1-packed-wd10.pdf > > A packed virtqueue is different from a split virtqueue in that it > consists of only a single descriptor ring that replaces available and > used ring, index and descriptor pointers. > > Each descriptor is readable and writable and has a flags field. These flags > will mark if a descriptor is available or used. To detect new available descriptors > even after the ring has wrapped, device and driver each have a > single-bit wrap counter that is flipped from 0 to 1 and vice versa every time > the last descriptor in the ring is used/made available. > > With this patch set I see performance equal or slightly better (+2-3%) in a PVP > scenario compared to split virtqueues (v18.11 in host) > > regards, > Jens > > > v11->v12: > * add a patch to disable control vq when packed vq is enabled. > I have a patch to support this but it needs a bit more work > and I think it shouldn't stop this series from being applied > * rework mergeable receive buffer code to be more efficient, by > batching descriptor refill, similar to what Maxime proposed for > split virtqueues > * removed unnecessary checks in virtio_recv_mergeable_pkts_packed > (Maxime) > * Did not merge receive functions as Maxime suggested because it seemed > to cause a small performance regression > * Move event_flags_shadow from patch 3 to 1 (Maxime) > * Did not merge xmit functions and call _split/_packed functions from > there because it seemed to cause small performance drop (-0.5%) > (Maxime) > > v10-v11: > * this version includes some fixes from Tiwei, so I added his > Signed-off-by to some of the patches > * fix hang with mergable rx buffers (Tiwei) > * clean-up code and simplify buffer handling (Tiwei) > * rebase to current virtio-next master branch > > v9-v10: > * don't mix index into buffer list and descriptors > * whitespace and formatting issues > * remove "VQ:" in dump virtqueue patch > * add extra packed vring struct to virtqueue and change function > prototypes and code accordingly > * move wrap_counters to virtqueue > * make if-conditions for packed and !packed more clear in > set_rxtx_funcs() > * initialize wrap counters in first patch, instead of rx and tx > implementation patch > * make virtio-user not supported with packed virtqueues, to > be fixed in other patch set? > > v8-v9: > * fix virtio_ring_free_chain_packed() to handle descriptors > correctly in case of out-of-order > * fix check in virtqueue_xmit_cleanup_packed() to improve performance > > v7->v8: > * move desc_is_used change to correct patch > * remove trailing newline > * correct xmit code, flags update and memory barrier > * move packed desc init to dedicated function, split > and packed variant > > > Jens Freimann (9): > net/virtio: vring init for packed queues > net/virtio: add packed virtqueue defines > net/virtio: add packed virtqueue helpers > net/virtio: dump packed virtqueue data > net/virtio: implement transmit path for packed queues Note that the series build is broken until this patch. > net/virtio: implement receive path for packed queues > net/virtio: add virtio send command packed queue support > net/virtio-user: ctrl virtqueue not supported with packed vqs > net/virtio: enable packed virtqueues by default > > Yuanhan Liu (1): > net/virtio-user: add option to use packed queues > > drivers/net/virtio/virtio_ethdev.c | 227 +++++-- > drivers/net/virtio/virtio_ethdev.h | 8 + > drivers/net/virtio/virtio_pci.h | 7 + > drivers/net/virtio/virtio_ring.h | 64 +- > drivers/net/virtio/virtio_rxtx.c | 620 +++++++++++++++++- > .../net/virtio/virtio_user/virtio_user_dev.c | 25 +- > .../net/virtio/virtio_user/virtio_user_dev.h | 2 +- > drivers/net/virtio/virtio_user_ethdev.c | 14 +- > drivers/net/virtio/virtqueue.c | 22 + > drivers/net/virtio/virtqueue.h | 122 +++- > 10 files changed, 1035 insertions(+), 76 deletions(-) >